Sealing devices may be utilized for the occlusion of many types of tissue openings, such as septal defects, PFO, and the like.
Tissue openings have traditionally been corrected by open-heart surgery. In order to avoid the trauma and complications associated with open-heart surgery, a variety of trans-catheter closure techniques have been implemented. In such techniques, an occluding device is usually delivered through a catheter to the site of the opening or defect. A device is placed into the defect and permanently deployed.
A variety of trans-catheter delivered devices are known. These include devices that require assembly at the site of the tissue opening or require threading or “buttoning” of the discrete device elements. Other devices include self-expanding devices. These self-expanding devices tend to be difficult to visualize, cumbersome to load, difficult to position at the site of a tissue opening, and reposition. Many self-expanding devices do not conform to heart anatomy, which can lead to tissue erosion.
An example of a self-expanding device includes an occlusion bag, a tube component, a guide catheter, a super elastic wire, a release mechanism and a delivery sheath. The super elastic wire is attached to the release mechanism. The wire, release mechanism, occlusion bag, guide catheter and tube component are inserted into a delivery sheath for transport to the aperture. After delivery, the occlusion bag is placed within the aperture and the wire is deployed within the bag. The bag and wire are repositioned if necessary, and the release mechanism is activated to release the wire.
Another example of a self-expanding device includes a shape set tubular metal fabric device and optionally, an occluding fiber included in the hollow portions of the device. The metal fabric defines a medical device shaped like a bell, which can be collapsed for passage through a catheter for deployment in a channel of a patient's body.
While these and other self-expanding devices are designed for trans-catheter delivery, they require assembly either prior to use or during use. They are also difficult to reposition or retrieve once deployed and provide poor conformity to heart anatomy. For these reasons, it would be desirable to provide an improved sealing device for use in trans-catheter techniques. Such sealing devices would in some embodiments have improved conformity to heart anatomy and be easily deployed, repositioned, and retrieved at the opening site.
Trans-catheter self-expanding sealing devices may be delivered and deployed by a variety of means. Most trans-catheter delivery devices choose one of two basic systems for deploying the device: pulling back an outer catheter to release the device, or pushing the device free of the catheter with a push rod. Each of these systems utilizes a handle to actuate the mechanism used to deploy the device. An example of such a system includes a flexible urging member for urging the sealing device through a catheter and a remotely located control means for advancing the urging member. In this example, the control means includes a threaded, tubular shaft connected to the urging member and a manually rotatable threaded rotor mounted on the shaft. The threads on the rotor mate with the threads on the shaft so that the rotation of the rotor through a known angle will advance the shaft and the urging member a known distance.
An example of a system that utilizes a pull back outer shaft or catheter includes a handle that may selectively hold the delivery system components at any configuration during deployment and positioning of the device. The outer catheter of such a system would be pulled back to release the device by actuating a sliding lever and a rotating finger ring on the delivery system handle.
While these and other device delivery systems are designed for trans-catheter device deployment, they require the use of a threaded rotor, which can become difficult to rotate, or they require large forces to pull back the outer catheter to expose the entire length of the constrained device. Many deployment systems are either not reversible or very difficult to reverse once the deployment procedure has taken place. For these reasons, it would be desirable to provide an improved delivery system for a sealing device. Such delivery system would, in some embodiments, have a handle able to be operated simply with a single hand and would be able to execute multiple manipulations with minimal force or hand movement.